4 Things Pharmacists Should Know About Medical Marijuana

What are the potential risks and benefits of medical marijuana? Should hospitals open their own dispensaries? Can medical marijuana decrease opioid mortality?

These were some of the questions discussed at the 2015 American Society of Health-System Pharmacists Midyear meeting on December 6, 2015.

Lee Kral, PharmD, BCPS, Jennifer Strickland, PharmD, BCPS, and Ernest J. Dole, PharmD, BCPS, provided many perspectives on medical marijuana, including the drug’s risks and benefits.

On the one hand, medical marijuana has been shown to have utility in treating pain.

Research provides evidence that it can help prevent paclitaxel-induced neuropathy and reduce pain among patients with cancer, osteoporosis, and brachial plexus avulsion. The drug has also been shown to have a calming effect on patients with fibromyalgia.

Some other benefits include its use as an appetite stimulant, antiemetic, antispasmodic, analgesic, and anticonvulsant. The drug can also lower intraocular pressure.

Plus, no fatal overdose of cannabis alone has been reported, and acute medical risks of THC are low, Dr. Dole pointed out. Marijuana is also less lethal than alcohol, opiates, barbiturates, and some common medications.

On the other hand, aside from the fact that marijuana is not approved by the FDA, some people suggest it is a gateway drug.

Dr. Kral discussed one survey of patients with a long history of substance abuse. The researchers asked how they got started using drugs, and the majority of the patients said alcohol or marijuana was their first substance. In addition, many said they strongly believed these were gateway drugs.

In addition, Dr. Kral noted that patients who combine THC and opioids are putting themselves at risk.

Patients who use cannabis have a higher prevalence of nonmedical opioid use in the past year than those who do not use THC, Dr. Kral noted.

Cannabis use is also associated with faster relapse to alcohol, cocaine, and heroin use. In addition, it may pose cardiovascular risks, as well as a risk for COPD and dependence. Another concern is its effects on adolescent development, memory, and psychiatric illness.

In Dr. Dole’s opinion, marijuana has benefits, but more research is needed to support this claim.

“It’s incredibly muddy waters,” Dr. Dole said.

Regardless of one’s opinion on medical marijuana, here are 4 facts health-system pharmacists should know:

1. There is some evidence that medical marijuana can boost the analgesic effect of opioids and decrease overdose risk.

The main takeaways from Dr. Dole were that medical cannabis for chronic pain can be effective and enhance the analgesic effect of opioid medications.

He discussed some research that suggested cannabis use is linked with positive treatment prognosis among opioid-dependent patients.

Using marijuana intermittently is associated with improved medication compliance on naltrexone, as well. Cannabis abuse and dependence may also be predictive of decreased heroin and cocaine use during treatment.

Opioid users may benefit from cannabis use during withdrawal, as well. States with medical cannabis laws have a 24.8% lower mean annual opioid overdose mortality rate, too.

2. THC use and driving do not mix.

If health-system pharmacists know that their patients are using marijuana, one thing they can do to help is educate them on the dangers of driving while under the influence of THC.

One statistic to share is that THC contributed to 12% of fatal crashes in 2010, Dr. Kral noted.

In addition, those who have been drinking and smoking or ingesting THC face 24 times the risk of a fatal crash. THC can also delay reaction time and can lead to more “incorrect responses” to emergencies, Dr. Kral said.

Some signs of a driver under the influence of THC include swerving outside the lane and more time needed to break when a sudden light change occurs.

3. Laws are murky on how hospitals should handle medical marijuana.

State and federal laws conflict on the use of marijuana, and most state laws do not address the use of the drug in hospitals.

Dr. Strickland said pharmacists should pay particular attention to this federal compliance issue.

One question is: If hospitals have to certify that they comply with federal laws, would allowing medical marijuana put them at risk for losing federal funding?

Dr. Strickland noted that individual hospitals could potentially lose millions of dollars, grants, or their nonprofit status. They could also face fines or other penalties. Hospitals could also lose their license, or their credentialing could be affected.

Another question is whether hospitals should open dispensaries in order to ensure access for patients and to allow for more research or revenue. Hospitals will have to consider how to handle informed consent policies, guidelines on patient selection and contraindications, training programs, the use of medical marijuana onsite, and the monitoring of outcomes.

4. Pharmacists will need more guidance on their roles are in dispensing medical cannabis.

“One could argue that pharmacists are the best positioned to manage this,” Dr. Strickland said. However, she also pointed out that what the pharmacist’s role entails remains unclear.

Currently, physicians can be held liable if they do not discuss drug risks with the patient, as well as possible drug-drug interactions. These are 2 areas pharmacists may need to focus on for patients in the future.